ONPREM AD sync with different domain

Question

Hi all,
What would be the different options to sync below scenario.

Their is a domain A which has on prem AD and domain B has onprem AD and azure AD connected to sync with AD connect. Now question is how domain B can be synced to on prem AD of domain B or directly to Azure AD of domain B..so that VM from domain A can be migrated to azure tenant of domain B and still access same stuff from domain A .

One way is my establishing trust between domain A and B on prem. Is their any other way using azure AD connect or some other methods.

Answer 1

Hello @naresh m

Thank you for reaching out.

Yes, you can sync users from multiple domains, in multiple forests to single Azure AD tenant. When you have multiple forests, all forests must be reachable by a single Azure AD Connect sync server. The server must be joined to a domain. If necessary to reach all forests, you can place the AD Connect server in a perimeter network (also known as DMZ, demilitarized zone, and screened subnet).

Additionally, I would like to confirm that only wat to achieve this would be to have two-way trust between these forests. The Azure AD Connect installation wizard offers several options to consolidate users who are represented in multiple forests/domains. The goal is that a user is represented only once in Azure AD.

You can review following article to get more details on support topologies: Topologies for Azure AD Connect.

Similar question has been answered on following QnA post: Sync multiple on-prem AD Domian to singe Azure AD tenant

I hope this helps.

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Answer 2

The easiest way is configuring the AD account UPNs (User Principal Name) to match the primary emails. If you follow the official guidelines, you should be fine (Prepare a non-routable domain for directory synchronization).